The present invention relates to an assembly for interconnecting two annularly shaped components and more particularly to an assembly for coupling annularly shaped jet propulsion engine components to each other so that loads are transmitted only in an axial direction from one member to the other.
In the past, many components of a cylindrical or annular shape have been attached to aircraft jet propulsion engines by conventional, rigid radial flange connections. For example, the fan inlet cowling is attached to the fan casing in a conventional manner by radial flanges that have mutually opposing abutment surfaces. These radial flanges are removably interconnected by threaded or other conventional fasteners.
The advent of high bypass turbofan jet propulsion jet engines has resulted in problems arising from the interconnection of components such as fan inlet cowlings to the fan casings in the conventional manner. The dynamic forces exerted on a fan inlet, for example upon takeoff, result in a bending moment being transferred through the flange interconnections from the inlet to the fan casing. The bending moments cause distortions in the fan casing, which can cause the fan casing to contact the fan blades, resulting in excess blade and tip seal wear, loss of engine performance, and increased fuel consumption.
It is, therefore, an object of the present invention to reduce the blade and tip seal wear, to increase performance of turbofan jet propulsion engines upon takeoff and cruise, and to decrease fuel consumption. More particularly, it is an object of the present invention to prevent bending moments from being transferred from a fan inlet of a jet propulsion engine to the fan casing and thus to eliminate distortions in the fan casing. In a broader sense, it is an object of the present invention to create a flange coupling assembly for two annular or cylindrical aircraft components that will transfer only axial loads between the members while allowing one of the annular members, for example a fan inlet, to move angularly relative to the other of the annular members, for example a fan casing.